Well-drilling tool.



1. C. THERIQT. WELL DRILLING TOOL. vAPPucATmN FILED ma. 27. 1914.

3mm/vtm r.. .w nu.. 6 M/ A a, m 1a ,fr 1 T n l| W c w J n wv Ul is heldwithin a collar at the lower end of a` 'citizen 'of theUnited States,vTait, in the county of Kern JAMES c. Timmer, or mnrncnuronnm.

f anion.

WELL-DRILLING- TOOL.

Applicant@ fixed Maren 27, 1914. serial no. 327,688.

'T0 all whomz't may concern Be it known that I, JAMES C. THnRro'r, ya

and lState of California, have invented certain new and usefulImprovements in Well-Drilling Tools;

and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains' to make and use the same. I, v

This invention relates to well drilling tools, and one of the principalobjects of the invention is to provide reliable and e'liicicnt means forrecovering the drill bit after it has become detached from the rotarydrill casing. In ordinary well drilling, where rotary drills and'drilling bits are used, the drill bit casing made up of a number ofsections connected together. lVhcn the bit strikes a hard refractorysubstance or formation, there is a great torsional strain uponthecasing, and this strain is frequently suilicient to twist the casing anddrop the drill bit and collar to the bottom of the well. To recover thebit and broken portion of the casing requires considerable time and isvery eX- pensive in practice.

One of the principal objects of this inven tion is to',` providereliable andeiiicient means for preventing the bit from droppin anygreat distance in case the drill'v casing s ould be' twisted oil". Ithas been found in practice thatthe drill casing usually parts at a pointwithin the first three'or four sections of the casing .adjacent to thebit or tool.

The objects and advantages above referred to may be attained'by. meansof the construc-I tion illustrated in the accompanying drawing, inwhich,

Figure 1 is a longitudinal sectional View taken through a safety devicemade in accordance with this invention, lportions being broken awaybetween thecollars and rings, and Fig'. 2 is a side elevation ot thedevice, portions being broken away between the co1- lar's and the devicebeing shown on a smaller scale than that shown in Fig. 1.

Referring to the drawing, the. numeralv 1. designates a drill collarwhich is inteiorly screw threaded at 2 for the? connection ofSpecification of `Letters Ivatent.

residing at P atentedApr. 6, 1915.

inner safety casing 4. The collar. 1 is also providedwith an interiorscrew threaded portion 5 at its upper end in whichfis fittedthe rotarycasing 6.y The casing 6 is made l up of a series of separate sectionsconnected. Atogether by interiorly screw threaded collars 7, andinterposed between the meetingends l of the sections 6 are steelunthreaded rings Y 8, which are substantially rectangular in l crosssection, and are fitted to slide upon the inner safety casing 4. Thesections 4 of the- Vinner safety casing areconnected together by meansof collars9, and these collars are disposed some distance above thevsteel rings 8. Anysuitable number of the sections v6 70 may beconnected together and the safety casing sections 4 are extended toconform to the length of the casing 6. A- packing of hemp, rubber,leather or other suitable-may terial 10 surrounds a core 11 whichconforms 75 to the side Iof thev inner safety casing 4, said l packingbeing interposed between the outer ofi by the excessive strain upon thedrilling i bit, andthe break occurs Within the area of the three or fourjointsat the lower end of i the casing 6, the safety inner casing 4would slide within the steel rings 8 and would stop when one of thecollars 9 came into cntact V9'0 with said rings thus preventingthe l'ssof the tool and permitting the latter to be readily withdrawn from thewell for repairs;

Various changes may be made in the de.- tails of construction without,departing from the spirit and'scope of the invention as defined in theclaim. l

lil/hat is claimed is l A safety device for the purpose describedcomprising. an inner casing-and an outer leo casing, steel rings mountedto move uponl the inner casing, a packing between the inner casing andouter casing and means for\ holding the packing in place.

In testimony whereof I affix my signature in presence of two4 witnesses.

, ,i AMES C. THERIOT. Vitnesses'. f

ELI BIGELow, R. "Wiri'rTnMoRn.

